Evaluation of In Vivo Antidiabetic Activity of Ethyl Acetate and n-Hexane Fractions of Raru Bark Extract (Cotylelobium melanoxylon) in Alloxan-Induced Diabetic Rat Model / Evaluasi Aktivitas Antidiabetes In Vivo dari Fraksi Etil Asetat dan n-Heksana Ekstrak Kulit Kayu Raru (Cotylelobium melanoxylon) pada Model Tikus Diabetes yang Diinduksi Aloksan

Introduction: Diabetes mellitus is a chronic metabolic disease with continuously increasing global prevalence, driving the search for safer and more effective alternative therapies based on natural ingredients. Raru bark (Cotylelobium melanoxylon) has been traditionally used as an antidiabetic agent, yet scientific evidence supporting the efficacy of its specific fractions remains limited. Methods: This laboratory experimental study evaluated the antidiabetic activity of ethyl acetate and n-hexane fractions of raru bark ethanol extract in alloxan-induced male Wistar rats (n=3 per group). Extraction was performed using maceration method with 96% ethanol, followed by sequential liquid-liquid fractionation. Simplicia characterization included determination of water content, total ash content, acid-insoluble ash content, as well as water-soluble and ethanol-soluble extractive values. Phytochemical screening was conducted qualitatively, while blood glucose levels were measured periodically over 14 days and analyzed using one-way ANOVA (p<0.05). Results: Simplicia characterization met the requirements of the Indonesian Herbal Pharmacopoeia with water content of 9.99%, total ash content of 1.78%, and acid-insoluble ash content of 0.19%. Phytochemical screening confirmed the presence of alkaloids, flavonoids, saponins, and tannins. The ethyl acetate fraction demonstrated more significant blood glucose reduction (318→95 mg/dL) compared to the n-hexane fraction (312→160 mg/dL) over the 14-day observation period, with a final mean value approaching that of the positive control (80.00±11.66 mg/dL). Statistical analysis revealed significant differences among treatment groups (p<0.05). Conclusion: The ethyl acetate fraction of raru bark extract exhibited superior in vivo antidiabetic activity compared to the n-hexane fraction in alloxan-induced diabetic rat models, correlating with the content of semi-polar compounds such as flavonoids and phenolics. The ethyl acetate fraction shows potential for development as a natural-based antidiabetic agent.

Pendahuluan: Diabetes melitus merupakan penyakit metabolik kronis dengan prevalensi global yang terus meningkat, mendorong pencarian terapi alternatif berbasis bahan alam yang lebih aman dan efektif. Kulit kayu raru (Cotylelobium melanoxylon) telah digunakan secara tradisional sebagai antidiabetes, namun bukti ilmiah yang mendukung efektivitas fraksi spesifiknya masih terbatas. Metode: Penelitian eksperimental laboratorium ini mengevaluasi aktivitas antidiabetes fraksi etil asetat dan n-heksana ekstrak etanol kulit kayu raru pada tikus Wistar jantan yang diinduksi aloksan (n=3 per kelompok). Ekstraksi dilakukan dengan metode maserasi menggunakan etanol 96%, dilanjutkan fraksinasi cair-cair bertingkat. Karakterisasi simplisia meliputi penetapan kadar air, kadar abu total, kadar abu tidak larut asam, serta kadar sari larut air dan etanol. Skrining fitokimia dilakukan secara kualitatif, sementara pengukuran kadar glukosa darah dilakukan secara periodik selama 14 hari dan dianalisis menggunakan ANOVA satu arah (p<0,05). Hasil: Karakterisasi simplisia memenuhi persyaratan Farmakope Herbal Indonesia dengan kadar air 9,99%, kadar abu total 1,78%, dan kadar abu tidak larut asam 0,19%. Skrining fitokimia mengkonfirmasi keberadaan alkaloid, flavonoid, saponin, dan tanin. Fraksi etil asetat menunjukkan penurunan kadar glukosa darah yang lebih signifikan (318→95 mg/dL) dibandingkan fraksi n-heksana (312→160 mg/dL) selama 14 hari pengamatan, dengan nilai rata-rata akhir mendekati kontrol positif (80,00±11,66 mg/dL). Analisis statistik menunjukkan perbedaan signifikan antar kelompok perlakuan (p<0,05). Kesimpulan: Fraksi etil asetat ekstrak kulit kayu raru menunjukkan aktivitas antidiabetes in vivo yang lebih unggul dibandingkan fraksi n-heksana pada model tikus diabetes yang diinduksi aloksan, yang berkorelasi dengan kandungan senyawa semi-polar seperti flavonoid dan fenolik. Fraksi etil asetat berpotensi dikembangkan sebagai agen antidiabetes berbasis bahan alam.